Optical scanners generate machine-readable image data representative of a scanned object, e.g., a paper document. Flatbed optical scanners are stationary devices which have a transparent, flat plate or platen upon which the object to be scanned is placed. The object is scanned by sequentially imaging narrow strips or scan line portions of the object on an imaging apparatus such as a charge-coupled device (CCD). The imaging apparatus produces image data which is representative of each scan line portion of the object which is imaged thereon.
In one type of flatbed scanner, the platen and the object remain stationary and at least a portion of the imaging assembly is moved relative to the object. The movement of the imaging apparatus changes the scan line portion which is currently being imaged. A flatbed optical scanner of the fixed platen type typically has a housing enclosing and shielding various optical and mechanical assemblies of the scanner. A transparent platen typically forms part of the top portion of the housing. The object being scanned is placed on the platen and the imaging apparatus moves beneath the platen to generate image data representing the object. The imaging apparatus moves a distance which is approximately equal to the length of the platen, thus, the housing is required to occupy an area at least as great as the platen.
An automatic document feeding mechanism may be attached to the scanner to alleviate the need for a user to place a document on the platen. When the scanner uses the automatic document feeding mechanism, the imaging apparatus typically remains stationary relative to the platen. The automatic document feeding mechanism moves the document over the platen past the imaging apparatus, thus, creating relative movement between the imaging apparatus and the document. Scan line portions of the document are converted to image data in the manner described above. The automatic document feeding mechanism typically bends the document as it moves the document over the platen. Thus, relatively rigid documents, such as photographs, cannot be placed through the automatic document feeding mechanism without the possibility of being damaged. Furthermore, a rigid document may not feed correctly, thereby causing the image data to be an incorrect representation of the object. Accordingly, when a rigid document is to be scanned, the document is generally manually placed on the platen and the imaging apparatus is moved in a manner as previously described.
The scanner outputs the image data representative of the scanned object to a computer, such as a desktop computer. The computer receives the image data and processes the image data per user instructions. These instructions may include printing or faxing a document representative of the processed image data and storing the image data.
Flatbed scanners are disclosed in the following patents, each of which is hereby incorporated by reference for all that is disclosed therein: Boyd et al., U.S. Pat. No. 4,926,041 for OPTICAL SCANNER; Boyd et al., U.S. Pat. No. 5,336,878 for VARIABLE SPEED SINGLE PASS COLOR OPTICAL SCANNER; Boyd et al., U.S. Pat. No. 5,038,028 for OPTICAL SCANNER APERTURE AND LIGHT SOURCE ASSEMBLY; Henry et al., U.S. Pat. No. 5,339,107 for COLOR OPTICAL SCANNER WITH ROTATING COLOR FILTER ASSEMBLY; Steinle et al., U.S. Pat. No. 5,410,347 for COLOR OPTICAL SCANNER WITH IMAGE REGISTRATION HOLDING ASSEMBLY; and Steinle et al., U.S. Pat. No. 5,646,394 for IMAGING DEVICE WITH BEAM STEERING CAPABILITY.
In recent years, the number of peripheral devices that may be connected to a computer has increased significantly. These peripheral devices include a printer, a pointing device, larger monitors than used in the past, and a scanner. These peripheral devices typically occupy desk space in the vicinity of the computer. As was described above, a flatbed scanner occupies an area at least as great as the platen, which is at least as great as the objects which it scans. In the case where the flatbed scanner is used to scan documents, the scanner occupies an area greater than the documents. Therefore, a need exists for a flatbed scanner that is able to scan large documents and rigid objects and occupies minimal area.